NON-PHARMACEUTICAL INTERVENTIONS AND BEHAVIORAL CHANGES
THAT MAY SAVE LIVES
Stan Finkelstein1, Shiva Prakash1, Karima Nigmatulina1,Tamar Klaiman2, Richard Larson1,3
1Engineering Systems Division, Massachusetts Institute of Technology, Cambridge,
Massachusetts 02139 USA
2O’Neill Center for National and Global Health Law, Georgetown University, 37th and O
Streets, NW, Washington, DC 20057 USA
Pandemic, Influenza, Public Health, Social Distancing, Non-Pharmaceutical Interventions
Work on this manuscript was supported by the Sloan Foundation of New York under
a grant entitled, "Decision-Oriented Analysis of Pandemic Flu Preparedness &
Response," and under a cooperative agreement with the U.S. Centers for Disease Control
and Prevention (CDC), grant number 1 PO1 TP000307-01, "LAMPS (Linking
Assessment and Measurement to Performance in PHEP Systems), awarded to the
Harvard School of Public Health Center for Public Health Preparedness (HSPHCPHP)
and the Massachusetts Institute of Technology (MIT), Center for Engineering Systems
Fundamentals (CESF). The discussion and conclusions in this chapter are those of the
authors and do not necessarily represent the views of the Sloan Foundation, the CDC, the
U.S. Department of Health and Human Services, Harvard or MIT. We gratefully acknowledge
the assistance of Marilyn Edobor, Alexander Flis, Stephen P Fournier and Katsunobu Sasanuma.
3 Corresponding author
77 Massachusetts Ave.
Cambridge, MA 02139-4307
The outbreak of novel A/H1N1 influenza in early 2009, eventually resulting in the declaration of
a pandemic by the World Health Organization, raises the spectre of past pandemics and their
devastating effects in terms both of economic consequences and, more important, human
mortality. In the United States, individual states are responsible for pandemic influenza
preparedness planning. A systematic review of state preparedness plans conducted prior to the
2009 outbreak reveals that a critical component of successful plans – namely, non-
pharmaceutical interventions (NPIs) related to hygiene, social distancing, and technology – are
incorporated to a far lesser degree than is necessary to ensure that the United States can
successfully meet the challenge of pandemic influenza.
INTRODUCTION AND BACKGROUND
In April 2009, cases of influenza caused by a strain of A/H1N1 virus that had not
previously been seen in humans began to be reported in Mexico. The strain’s genome included
material of swine, avian, and human origin and came to be referred to as the “swine flu.” By
mid-June, this novel H1N1 had spread to more than 70 countries. By June 11, the World Health
Organization declared a full-fledged pandemic.
For several years prior to this 2009 event, concern by scientists and medical professionals
the world over focused on the potential threat of a form of Influenza A virus subtype H5N1, also
known as A(H5N1), which can cause illness in humans and many other animal species. Its bird-
adapted strain – HPAI A(H5N1) – is familiar to most as “avian influenza” or “bird flu,” and has
become endemic in many bird populations, particularly in Southeast Asia. Already, it has killed
millions of birds and forced humans to slaughter and dispose of hundreds of millions of others to
halt its proliferation. Another strain, Z+, is a growing killing machine among pigs, cats, and
mice, and has mutated to become proficient in getting deep into human lung tissue and
destroying it – with death a likely result. It has also been found to be a powerful weapon against
the human central nervous system. Avian influenza A(H5N1) “is progressively adapting to
mammals and becoming more neurologically virulent” (De Jong, 2005). As H5N1 in birds
spreads across the globe, the threat of yet another pandemic heightens and accelerates. The strain
mutates quickly, making it difficult for researchers developing medicines to keep pace. So, at
present we are fighting one confirmed influenza pandemic and face the threat of another much
more dangerous one.
The pressing question is whether history will repeat. In the Christmas 1918 edition, the
editors of the Journal of the American Medical Association published an ominous comment:
“The year 1918 has gone: a year momentous as the termination of the most cruel war in the
annals of the human race; a year which marked, the end at least for a time, of man’s destruction
of man; unfortunately a year in which developed a most fatal infectious disease causing the death
of hundreds of thousands of human beings. Medical science for four and one-half years devoted
itself to putting men on the firing line and keeping them there. Now it must turn with its whole
might to combating the greatest enemy of all – infectious disease.”
The new enemy was pandemic influenza. Just as World War I was coming to a close,
having cost the world 20 million deaths and 21 million wounded (both military and civilian),
something far more deadly was emerging. The influenza pandemic of 1918-1919 knew no
borders, and no army could be mustered against it in battle. Its brutal reach was far greater than
that of the war: upwards of one-third of the world’s population was infected (as many as 500
million people), and the death toll reached nearly 50 million. Hardest hit were people ages 20 to
40, contradicting the history of the disease, which had always primarily killed young children
and the elderly.
While our collective consciousness “remembers” the Black Death or Bubonic Plague of
1347-1351, the pandemic of less than a century ago killed more people in a single year. It is
likely the most devastating pandemic in recorded human history. A few more of the staggering
statistics from that period are worth repeating.
· About 28 percent of all Americans were infected (Tice, 1997).
· The average lifespan in the United States was diminished by 10 years.
· The mortality rate was 2.5 percent, compared with less than 0.1 percent in previous
epidemics (Taubenberger et al., 1997).
Why do we speak of those events with such urgency? The statistics will likely pale in
comparison to what might occur today, if we are not prepared. The alarm now sounds for the
potential effects of pandemic influenza in a world with a far larger and often more densely
concentrated urban population and in which the ease of travel, and hence human-to-human
contact, makes 1918-1919 look like a prehistoric era.
Faced with even the possibility of any sort of viral pandemic, most attention is typically
paid to medical interventions, including vaccines and anti-viral medications. Vaccines and drugs,
which take time to discover and produce, are little match for pandemic influenza if the objective
is to slow the spread of the sickness.
Considerable experience has been gained in developing vaccines for a seasonal outbreak
of influenza. A vaccine is only useful if it corresponds to the strain of influenza by which we
come under attack. No one can predict with perfect accuracy the strain we will be fighting
because viruses constantly mutate. Thus, we cannot count completely on any of the coming
vaccines being exactly what we need. The technical solution of vaccines, available before the
influenza hits, involves guesswork. By the time the dominant strain has been fully characterized,
it is already producing human cases. And it will take, typically four to six months to manufacture
it, and even longer before it can be distributed to those at risk. If the experts guess incorrectly,
the population gets little protection from the vaccine. When the threat is an impending flu
pandemic and the viral culprit had not been seen before, the vaccine will first become available
late in the progression of the disease.
There is a role for anti-viral drugs in treating novel influenza, as long as the flu strain is
not resistant to them. Even if adequate supplies of these medications are available, the logistics
of distributing them are complex. And the very short time window within which symptomatic
individuals must ingest these medicines in order to receive benefit will greatly limit their value in
preventing spread of the disease throughout the population.
There are, however, other critical steps that can be taken that are powerful, effective,
relatively inexpensive, and do not correspond to gambling on vaccines and drugs. These non-
pharmaceutical interventions (NPIs) involve either hygiene or social distancing measures. Since
influenza is transmitted through the respiratory emissions of ill individuals when they cough,
sneeze, or talk, there is widespread agreement that hygiene measures such as proper hand
washing, wearing of masks, and particular ways of covering the mouth when coughing or
sneezing can be effective ways to reduce the spread and severity of a pandemic. Social